Method of and apparatus for treating material to be sprayed



Ap 20, 1954 KEMPTHORNE 2,676,059

J. L. METHOD OF AND APPARATUS FOR TREATING MATERIAL TO BE SPRAYED FiledFeb. 8, 1951 .2 Sheets-Sheet 1 mmmIHIIlI/l I INVENTOR. rhme Lfizzzvifiozwe BY A TTORNEY April 20, 1954 J. L. KEMPTHORNE 2,676,059 METHODOF AND APPARATUS FOR TREATING MATERIAL TO BE SPRAYED Filed Feb. 8, 1951I 2 Sheets-Sheet 2 INVENTOR. rfames lfim ozriarae ATTORNEY Patented Apr.20, 1954 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR TREAT-INGr MATERIAL TO BE SPRAYED 2 Claims.

This invention relates to improvements in spraying apparatus and moreparticularly to a method of and unit for treating the material passedthrough such apparatus. The apparatus referred to are used for thespraying of asbestos fiber and other acoustical and thermal insulationmaterials. The materials to be sprayed, such as asbestos fibers and thelike, are usually passed through the apparatus in the form of a streamof loose particles which stir up a considerable amount of dust. The dustproblem has been so serious as to impair the health of workmen andcreate untidy conditions. Other trades frequently refuse to work in thesame location at which insulation materials are being applied for thereasons mentioned. The fibrous materials, such as asbestos, are ofamorphous cross-sectional outline, presenting a large and highlyirregular surface outline which tends to have an abrasive effect on theblower and other parts of the apparatus through which the same passes.

Such materials have been projected from a gun head, with adhesivematerials sprayed from the end of the head into the path of the fibersleaving the spray gun, but it has been found that the fibers tend toflower out upon leaving the spray gun head, as they are moved up to thatpoint through the apparatus at greater than atmospheric pressure. Uponleaving the spray gun head and moving into the atmosphere, thematerials, by virtue of reduced pressure, tend to flower out and haverandom movement, stirring up substantial amounts of dust. Theapplication of adhesive to the material leaving the spray gun head bymethods old in the art, is inaccurate and difiicult; the materialleaving the gun head flowers out as above noted; furthermore, theadhesive penetrates the mass irregularly, leaving layers of dry fiberswhich fall off the surface to be coated.

The present invention is designed to overcome the objections above notedso that the material will pass through the apparatus without stirring updust and without the usual abrasive action, the material further leavingthe gun head and continuing onto the surface to be coated in a straightline. Pursuant to the invention, a treatl ng unit is provided having adischarge end for connection to the apparatus into the path of thematerial passing through the apparatus so as to apply a spray mist tosaid stream which will mingle and blend with the stream of particles toovercome the objections referred to and obtain advantages which willbecome apparent from the description below and by reference to theaccompanying drawing.

Pursuant to the invention, the fiber stream is thoroughly and uniformlywetted in two stagesthe first or initial stage occurring on movement ofthe stream through the apparatus, the second or completion stageoccurring in mid-air on projection of the stream from the apparatus.

The drawings show an apparatus embodying the invention comprising ahopper provided with means to meter the fiber through a dischargeopening thereof, a suction blower connected to said hop-per dischargeopening by means of a pipe having an inlet opening adjacent the hopperdischarge opening, and a treating unit to wet the fibers opening intothe pipe, so that on operation of the blower, the mist from the treatingunit and the fiber stream treated thereby will be constantly drawnbeyond said inlet and into the blower.

In the drawings:

Fig. l is a fragmentary elevational and schematic view of an insulationmaterial spraying apparatus having applied thereto a treating unit ofthe invention,

Fig. 2 is an elevational view of said material treating unit positionedwith the discharge end thereof disposed in a perpendicular plane to thepath of movement of the fibrous material from the discharge opening ofthe hopper, the latter being indicated fragmentarily in said figure,

'Fig. 3 is a fragmentary perspective view of an apparatus embodying theinvention,

Fig. 4 is an elevational view of said apparatus,

Fig. 5 is a similar view showing the invention applied to a tandemblower arrangement,

Fig. 6 Ba schematic view of another form. of the invention, and

Fig. 7 is a perspective view of another form of the invention.

As shown in the drawings, the invention applied to an apparatus H] forthe movement, at greater than atmospheric pressure, of particles offibrous material in a stream of random, loose form, from a hopper llthrough blower l2 and through bore i3 of spray gun M and toward thesurface S to be coated. The material moves in the path it defined by thevarious parts of the apparatus, including pipe 35 connecting thedischarge opening 3 3 of hopper ll with inlet opening 33 ofblower [2,for example, in apparatus constructed in that form. The path 55 of material through the apparatus continues through the discharge end ll ofblower l2 and then out of the apparatus, as, for example, through hose38 and out of bore E3 of spray gun head Hi and onto the surface S to becoated. The apparatus, in the form shown in the drawings and abovereferred to, exemplifies one of many different types of sprayingapparatus to which the invention may be applied. The invention isapplicable to apparatus for the spraying of a fibrous material from ahopper and through a spray gun in the path defined by the apparatus. Thepoint of discharge of the fiber stream from the apparatus at 41 may bebore I3 of spray gun I4 or any other bore or opening through which thestream of fibers may be projected, and the reference, in thisapplication, to bore I3 of spray gun I4 shall be deemed to include anyother projection opening or means in the apparatus to the same orsimilar end. In the drawings, the path of the material through theapparatus is designated by reference character I5, the direction ofmovement of the particles in said path being indicated by the arrow I5(Fig. 1).

The material treating unit of the invention comprises a mixing tube 2|having a discharge end 22 for connection to the apparatus so as to openinto path I5 at a plane 23 (Fig. 2) at right angles to the axis of saidpath. Air and water lines 25, 25 are connected to opposite ends ofmixing tube 2!, so that the water entering the tube will, at thedischarge end thereof, enter and cross said path I5 in the form of aspray mist, mingling and blending with the stream of particles andaccompanying said stream in its continued movement in path I5 and out ofbore I 3 of the spray gun.

In Figs. 1 and 4, apparatus embodying the invention is shown, comprisinhopper i I provided with means, such as brush 33, to meter the fiberdeposited into the hopper through discharge opening 34 thereof. Suctionblower It is connected to hopper discharge openingtsi by means of pipe35 having air inlet opening I8 adjacent hopper discharge openin 34.Treatin unit 2i opens into pipe 35 preferably at a point past inletopening I8 thereof. On operation of blower I2, the mist discharged at 22by treating unit 20 and the fibers treated thereby will be constantlydrawn beyond inlet I 8 and into blower I2. When thus treated, it isfound that the stream of .particles will continue its movement in theaxial plane of the bore I3 of the spray gun and in the cross-sectionalform of said bore in a straight line through the atmospheric pressure atthe end of the spray gun bore and toward the surface S to be coated.

It has been found in practice that the treatment of the material,pursuant to the invention, results in the following advantages: Dustparticles previously encountered in the movement of the particlesthrough the apparatus are substantially eliminated. The spray mist fromthe discharge end 22 of mixing tube 25 thoroughly mingles and blendswith the stream of particles so that said stream will continue in astraight projected line corresponding to that of the axial plane of boreI3 of the spray gun head, past the spray gun head and onto surface S.The stream of particles will be held together so as to form a morecompact and better unified stream which will not flower out at thereduced pressure (atmospheric) encountered upon leavin the spray gunhead.

The spraying apparatus Ill conventionally has motor driven means (BI,40) for the hopper and blower, having a circuit for connection to asource of power, including the wire 30 conventionally controlled by aswitch or the like. The motor 3I drives shaft 32 of brush 33 or the like4 which projects the insulation material through discharge opening 34 ofhopper II. This illustration is by way of example only of one of thevarious types of motor driven mechanisms known in the art for theprojection of said material through the apparatus. It is desirable thatthe water flowing through mixing tube 2% and ,into the apparatus be cutoff when motor 3! is shut off so that the treating unit will beoperative only when necessary. To that end, an electrical power valve,such as solenoid 28, may be provided to control the path of supply ofwater to the mixing tube. Said solenoid may be independently switchcontrolled or may be connected, as by wire 29, in series to the circuitindicated by wire 38 for motor 3I. Thus, the

.power valve 28 will be opened to permit of the fiow of water into saidmixing tube 2i only when the motor is on. A second solenoid 39 may beprovided for a similar purpose-to control air inlet 2 3. Hand-operatedvalves 25, 2? may be incorporated in mixing tube 2! or otherwiseassociated with said treating unit so as to enable the operator tocontrol the flow of water and air into the tube and their relativemixing ratios.

In Fig. 3, the treating unit 28 is shown secured to the apparatusintermediate the hopper and inlet port 36 of blower I2. By positioningthe unit at this point, abrasion of the blower unit fan incident to thepassage of dry particles of fibrous material and dust therethrough willbe substantially reduced. The invention is shown in Fig. 3 in itssimplest form, wherein a single treating unit 26 is suitably mounted inthe apparatus to intercept the fibers moving in a path through theapparatus. The stream of fibers is projected from the apparatus at avelocity and pressure determined by such factors as distance from theapparatus to the surface to be coated, thickness of coating of fibers tobe applied, and the like. The treating units may be used in tandern orother plural arrangement where necessitated by the job to be performed.

In Fig. 5, for example, a tandem arrangement of blowers is shown, thesecond blower 2a. increasing the pressure at which the stream of fiberswill be projected from the apparatus. In such case, a second treatingunit 26a may be secured to the apparatus to further wet the fiberstream.

Units may be secured to the apparatus to intercept the moving stream offibers at a number of different points in path I5 through the apparatus,as shown in Fig. 6, wherein, in addition to unit 2!! which interceptsthe stream of fibers between the hopper and blower, a second unit. 252)meets the stream after its passage throu h the blower.

The treating unit may be secured, as at 31 in Fig. '7, to the dischargeend I"! of the blower unit,

if desired, instead of between the hopper and blower, or to any otherpoint in the path I5 defined by the particles in passage through theapparatus.

The spray mist passes through the plane 23 defined by the discharge endof unit 28 preferably, as shown in the drawing, at right angles to pathI5 of movement of the particles through the apparatus, so that said mistwill efiectively intersect the movingparticles, thoroughly mingling andblending with the stream of particles, coating said particles andsetting up a mist which will accompany said stream in its continuedmovement in said path and out of the bore of the spray gun head. Theconnection of the electric valves 28 and/or 39 to the source of powermay be controlled by a single switch which also controls the current tothe motors for the hopper il and/or blower I2. It is deemed desirable,although not essential, in carrying out the invention, that the flow ofwater and/or air into the unit 28 be controlled by the use of solenoidor similar electrically actuated mechanisms 28, 35, or the like for thepurpose mentioned.

Pursuant to the invention disclosed in the application, the dustparticles which accompany the fibrous material in passage through theapparatus are moistened and weighted so that they will be confined bythe fiber stream moving therewith through and out of the apparatus. Thedust particles will not follow courses dictated by their normal randommovement when dry and will not tend to flower out on passing from thehigher pressures of apparatus to atmospheric or room pressure. Thepresent invention thus provides means for assuring the continuedmovement of the fiber stream out of the apparatus and toward the surfaceto be coated in a true projected path instead of in the objectionableflowering out or random movement.

In the conventional apparatus, the stream of fibers is discharged dry,accompanied by all of the dust generated in passage through theapparatus, so that the stream tends to flower out, discharge dust andstir up further dust in moving toward the surface S to be coated.Pursuant to the instant invention, the fiber stream 55 is projected fromthe apparatus as at 57 toward the surface to be coated, describing apath whose marginal edges it do not tend to flower out but tend toremain more constant, the stream of fibers being unaccompanied by randommoving dust particles and stirring up no dust in moving toward surfacesS.

The stream of fibers 45 will have been wetted in an initial or firststage while moving through the restricted path 55 defined in theapparatus, pursuant to the invention. The stream of fibers will then bereceptive to a second wetting or completion stage by action of nozzlesQ8, Q9 (Fig. 4) mounted on spray gun Hi and connected to suitable air,adhesive and water lines 43, 44 to project jets of adhesives, water orother liquid as noted at it, as. Jets 48', 59' converge as at 50 ontostream 5 in mid-air, and in the path of movement thereof toward surfaceS to be coated. The nozzles 58, at may be mounted elsewhere in theapparatus so that the jets will intercept stream 45 in mid-air at orbeyond point 41, but the arrangement above referred to, wherein thespray gun projects the stream of fibers 45 at a medial axial line from apoint 137, and the jets 48, 69' are located for tangential contact withthe stream 45 therebeyond, has been found to be admirably adapted toattain the objectives of the invention.

The term water, as used in this application, shall be deemed to includeother liquids suitable to the same ends.

The air and water line connections to the treating unit 20 may beconveniently made at the ends of tube 2 l, but said tube may be ofanother structural form, with the air and water lines connected theretoat other points, if desired. For example, the tube 2! may :be of theflexible hose type or otherwise extended and the air-water inlet andcontrol valves therefor may be at a point remote from the discharge end22 of the tube, if desired, within the scope and purview of theinvention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An apparatus of the character described, comprising a blower having acenter inlet and a peripheral outlet, a hopper having an outletaperture, mechanism in the hopper for discharging fibrous particlesthrough said outlet aperture, a pipe extending from th inlet of saidblower to the outlet of said hopper said pipe being of substantiallyequal cross sectional outline to said hopper aperture and forming aclosed connection between said aperture and the blower inlet except atits end communicating with the hopper said pipe at that point having aside opening constituting an air inlet through which air is drawn by theblower to mix with the fibrous material discharged from the hopper, atube over said pipe having a depending branch intermediate its lengthcommunicating with said pipe through the upper portion thereof, and at apoint spaced from the air inlet an air hose connected with one end ofsaid tube, a water hose connected with the other end of said tube,valves in said apparatus for regulating the air-water flow into saidtube, and a spraying hose extending from the outlet of said blower.

2. The structure recited in claim 1, wherein water tubes are mountedalong the spraying hose, and nozzles carried by the outer ends of thewater tubes spaced from each other circumferentially of the sprayinghose and disposed at an incline for causing the water sprayed therefromto intersect at a distance outwardly from the end of the spraying hose.

References (Jilted in the file of this patent UNITED STATES PATENTSNumber Name Date 2,125,860 Sommer Aug. 2, 1938 2,178,539 Hill et a1.Nov. 7, 1939 2,363,480 Brownies Nov. 28, 1944 2,442,206 Kempthorne May25, 1948 2,578,412 Fisher Dec. 11, 1951 2,585,004 Gillespie et a1 Feb.12, 1952

